Description

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Motorola was not napping when GE came out with the DTO-
series transistor powered Progress Line radiotelephone with built-in selector
and duplexer, although GE's duplexer appears to have beaten Motorola to the
market by several years. Motorola's choice was to introduce a completely new
design, a thoroughly modern mobile telephone with built-in duplexer and solid
state selector, about half the size of GE's DTO, and which was almost fully
transistorized. Motorola's TLD-1000 series "MTS" mobile was marketed
in July 1963, and drew heavily upon the design innovations featured in their
"Motrac" line of conventional two-way radios. The only vacuum tubes
used were the power amplifier and driver of the transmitter. There were no
relays; all switching was done with transistors. The basic platform of the
TLD1000 called for the capability to expand up to 11 channels, based upon the
FCC decision in the early 1960's to "split" existing VHF channels and
require "narrow band" 5 KHz deviation (versus the old "wide
band" 15 KHz deviation standard in mobile systems). The TLD-1000 was
developed under the IMTS contract mentioned below, however it was initially sold
as an MTS radio to be compatible with existing MTS systems, and to be upgraded
later to full IMTS capability.

The TLD-1000 used its own unique control head, with two
rows of clear plastic pushbuttons to select the necessary channels. The basic,
central portion of the control head can be seen to be a copy, in plastic, of the
original Western Electric 47 series control head. This Motorola unit was fully
accepted by Western Electric and usually will be found with an orange painted
"WE" number stamped on the chassis, but was also assigned a
"KS" number by Western Electric. The equipment could be configured for
"battery saving", which involved splitting the power input wiring for
the transmitter from the receiver. Unlike competitor's equipment, the Motorola
set used the exact spacing of the transmit and receive frequencies, in MHz, as
the receiver's IF frequency. In this way, it was only necessary to install one
crystal per channel, which was used by both the transmitter and the receiver. In
the TLD1000, the selector is mounted on a hinged bracket underneath the main
chassis. A rear set extension control head was available for limousines. The
"MTS" TLD1000 radio is essentially the same chassis as in Motorola's
famous "MJ" TLD1100 radio, which is described later under
"IMTS" equipment.

Note that the MTS control head shown in the brochure photo
below was also sold with an external MTS decoder for use on conventional Motrac
radio drawers, which were not duplex. This setup was usually found on the
low band "Z" channel equipment, which was never a duplex system,
although some VHF MTS systems used conventional Motrac radio drawers as well,
generally for telephone company owned vehicles and service crews.

There is an interesting example of the TLD-1000 head in
use in the opening scenes of the James Bond film Live and Let Die
where Bond is in the back seat of a CIA Chevrolet in New York and the driver
takes a call (before being shot and losing control of the car.)